Marek Malik

e-Health: a position statement of the European Society of Cardiology

e-Health encompasses the use of information and communication technologies (ICTs) in the support of health and health-related activity.1 It can be subdivided into several domains, listed in Table 1 .2 View this table: Table 1 The domains of e-health, involving healthcare administration and support, education, healthcare delivery, and research e-Health has the potential to provide innovate solutions to health issues, and is often viewed by politicians and healthcare professionals as a key ‘enabling’ technology to improve care and the experience of care for the those living with chronic conditions, particularly at a time of constrained healthcare funding. Behind all of this stands the individual/citizen/patient/customer, who is increasingly familiar with ICT and expects to find it supporting modern healthcare delivery, facilitating more personalized and person-centred care at the right time and in the right place. In theory, technological innovation should bring better inter-professional co-operation, information sharing, decision support, and flexibility to the healthcare system. However, there are important societal and professional constraints that reduce the impact of such innovation, including legal, ethical, and data protection issues. Healthcare professionals may be resistant to such innovation, particularly if the technologies are considered to be ‘solutions seeking a problem’ and where the evidence for the impact on quality of care is seen as less than robust. Indeed, ensuring proper integration of new technologies into the healthcare system is often difficult, requiring process redesign or ‘disruption’.6 Regulatory bodies, reimbursement authorities, and national and international political bodies often find it difficult to react quickly, or consistently, to this rapidly changing area. The European Union has an e-health action plan for 2012–2020, which states that the promise of ICT to increase efficiency, improve quality …

ICD risk stratification studies – EU-CERT-ICD and the European perspective

BACKGROUND AND RATIONALE In patients with ischemic or non-ischemic cardiomyopathy and impaired left ventricular ejection fraction, treatment with implantable cardioverter-defibrillator (ICD) has been shown to improve survival and guidelines recommend their use for primary prevention of sudden cardiac death. Experts disagree regarding the validity of decade-old trial results as the basis for this recommendation, therefore, reconsideration of prophylactic ICD treatment is needed. EU-CERT-ICD, DANISH-ICD AND DO-IT In order to update the evidence on prophylactic ICD treatment, several prospective studies are underway in Europe. The prospective EU-CERT-ICD cohort study (NCT 02064192) is enrolling 2500 patients and compares patients undergoing first ICD implantation with controls with an earlier clinical decision to go without ICD implantation strictly unrelated to the study. The DANISH ICD study (NCT 00542945) has randomized 1000 patients with dilated cardiomyopathy and an LVEF ≤35% (1:1 ICD implantation vs. control). The prospective DO-IT multicenter registry will include 1500 ICD patients in multiple Dutch high-volume implanting centers. Due to the widespread use of ICD therapy, new randomized trials seem not straightforward to envisage in many countries. CONCLUSION The above described ICD studies will provide additional evidence regarding the effectiveness of primary prophylactic ICDs in Europe and may have an impact on ICD treatment guidelines. They could also help to design randomized trials in low risk patients.

Clinical value of different QRS-T angle expressions

Abstract Aims Increased spatial angle between QRS complex and T wave loop orientations has repeatedly been shown to predict cardiac risk. However, there is no consensus on the methods for the calculation of the angle. This study compared the reproducibility and predictive power of three most common ways of QRS-T angle assessment. Methods and results Electrocardiograms of 352 healthy subjects, 941 survivors of acute myocardial infarction (MI), and 605 patients recorded prior to the implantation of automatic defibrillator [implantable cardioverter defibrillator (ICD)] were used to obtain QRS-T angle measurements by the maximum R to T (MRT), area R to T (ART), and total cosine R to T (TCRT) methods. The results were compared in terms of physiologic reproducibility and power to predict mortality in the cardiac patients during 5-year follow-up. Maximum R to T results were significantly less reproducible compared to the other two methods. Among both survivors of acute MI and ICD recipients, TCRT method was statistically significantly more powerful in predicting mortality during follow-up. Among the acute MI survivors, increased spatial QRS-T angle (TCRT assessment) was particularly powerful in predicting sudden cardiac death with the area under the receiver operator characteristic of 78% (90% confidence interval 63–90%). Among the ICD recipients, TCRT also predicted mortality significantly among patients with prolonged QRS complex duration when the spatial orientation of the QRS complex is poorly defined. Conclusion The TCRT method for the assessment of spatial QRS-T angle appears to offer important advantages in comparison to other methods of measurement. This approach should be included in future clinical studies of the QRS-T angle. The TCRT method might also be a reasonable candidate for the standardization of the QRS-T angle assessment.

T-wave loop area from a pre-implant 12-lead ECG is associated with appropriate ICD shocks

Aims In implantable cardioverter-defibrillator (ICD) patients, predictors of ICD shocks and mortality are needed to improve patient selection. Electrocardiographic (ECG) markers are simple to obtain and have been demonstrated to predict mortality. We aimed to assess the association of T-wave loop area and circularity with ICD shocks. Methods The study investigated patients with ICDs implanted between 1998 and 2010 for whom digital 12-lead ECGs (Schiller CS200 ECG-Network) of sufficient quality were obtained within 1 month prior to the implantation. T-wave loop area and circularity were calculated. Follow-up data of appropriate shocks were obtained during ICD clinic visits that included reviews of device stored electrograms. Results A total of 605 patients (82% males) were included; 68% had ischemic cardiomyopathy and 72% were treated for primary prevention. Over 3.8±1.4 years of follow-up, 114 patients (19%) experienced appropriate shock(s). Those with smaller T-wave loop area received fewer shocks (TLA, hazard ratio, HR, per increase of 1 technical unit, 0.71; [95% confidence interval, 0.53–0.94]; P = 0.02) and those with larger T-wave loop circularity (TLC) representing rounder T wave loop received more shocks (HR per 1% TLC increase 2.96; [0.85–10.36]; P = 0.09). When the quartile containing the largest TLA and TLC values, respectively, were compared to the remaining cases, TLA remained significantly associated with fewer and TLC with more frequent shocks also after multivariate adjustment for clinical variables (HR, 0.59 [0.35–0.99], P = 0.044; and 1.64 [1.08–2.49], P = 0.021, respectively). Conclusions The size and shape of the T-wave loop calculated from pre-implantation 12-lead ECGs are associated with appropriate ICD shocks.

Heart rate dependency of JT interval sections

BACKGROUND Little experience exists with the heart rate correction of J-Tpeak and Tpeak-Tend intervals. METHODS In a population of 176 female and 176 male healthy subjects aged 32.3±9.8 and 33.1±8.4years, respectively, curve-linear and linear relationship to heart rate was investigated for different sections of the JT interval defined by the proportions of the area under the vector magnitude of the reconstructed 3D vectorcardiographic loop. RESULTS The duration of the JT sub-section between approximately just before the T peak and almost the T end was found heart rate independent. Most of the JT heart rate dependency relates to the beginning of the interval. The duration of the terminal T wave tail is only weakly heart rate dependent. CONCLUSIONS The Tpeak-Tend is only minimally heart rate dependent and in studies not showing substantial heart rate changes does not need to be heart rate corrected. For any correction formula that has linear additive properties, heart rate correction of JT and JTpeak intervals is practically the same as of the QT interval. However, this does not apply to the formulas in the form of Int/RRa since they do not have linear additive properties.

Wavelet analysis of signal-averaged electrocardiograms : I. Design, clinical assessment, and reproducibility of the method

Background:Wavelet representation is able to detect low amplitude patterns even if hidden within signals of much higher amplitudes.

Association of the right ventricle impairment with electrocardiographic localization and related artery in patients with ST-elevation myocardial infarction

INTRODUCTION The right ventricular myocardial infarction (RVMI) has traditionally been mainly related to inferior wall ST elevation myocardial infarction (STEMI). This study assessed the RVMI electrocardiographic (ECG-RVMI) signs in relationship to ECG-based STEMI localization and to the infarct related artery in patients treated with primary percutaneous coronary intervention (pPCI). METHODS Three hundred consecutive adult patients (107 females) were referred to catheterization laboratory with the acute STEMI diagnosis. In all patients, both the standard 12-lead ECGs and the right-sided precordial leads (V1R-V6R) were recorded. ECG-RVMI was diagnosed by ST segment elevation above 100μV in V4R. RESULTS ECG signs of RVMI were found in 35 and 31 (23.8% for both) patients with inferior and anterior wall STEMI, respectively. In 32 ECG-RVMI patients, the right coronary artery (RCA) was occluded while in 34 patients, the occlusions were in the left anterior descending (LAD) or the left circumflex artery. No statistically significant differences were found in ECG-RVMI patients when comparing clinical variables between those with anterior and inferior wall STEMI. CONCLUSIONS ECG signs of RVMI during acute STEMI are not uncommon. RCA was the infarction-related artery in only one half of these patients. Anterior wall STEMI and the LAD were associated with a significant proportion of ECG-RVMI cases.

Sex differences in long-term mortality among acute myocardial infarction patients: Results from the ISAR-RISK and ART studies

Background Mortality rates in females who survived acute myocardial infarction (AMI) exceed those in males. Differences between sexes in age, cardiovascular risk factors and revascularization therapy have been proposed as possible reasons. Objective To select sets of female and male patients comparable in respect of relevant risk factors in order to compare the sex-specific risk in a systematic manner. Methods Data of the ISAR-RISK and ART studies were investigated. Patients were enrolled between 1996 and 2005 and suffered from AMI within 4 weeks prior to enrolment. Patients of each sex were selected with 1:1 equivalent age, previous AMI history, sinus-rhythm presence, hypertension, diabetes mellitus, smoking status, left ventricular ejection fraction (LVEF), and revascularization therapy. Survival times were compared between sex groups in the whole study cohort and in the matched cohort. Results Of 3840 consecutive AMI survivors, 994 (25.9%) were females and 2846 (74.1%) were males. Females were older and suffered more frequently from hypertension and diabetes mellitus. In the whole cohort, females showed an increased mortality with a hazard ratio (HR) of 1.54 compared to males (p<0.0001). The matched cohort comprised 802 patients of each sex and revealed a trend towards poorer survival in females (HR for female sex 1.14; p = 0.359). However, significant mortality differences with a higher risk in matched females was observed during the first year after AMI (HR = 1.61; p = 0.045) but not during the subsequent years. Conclusion Matched sub-groups of post-AMI patients showed a comparable long-term mortality. However, a female excess mortality remained during first year after AMI and cannot be explained by differences in age, cardiovascular risk factors, and modes of acute treatment. Other causal factors, including clinical as well as psychological and social aspects, need to be considered. Female post-AMI patients should be followed more actively particularly during the first year after AMI.

Adiponectin, biomarkers of inflammation and changes in cardiac autonomic function: Whitehall II study

BackgroundBiomarkers of inflammation and adiponectin are associated with cardiovascular autonomic neuropathy (CAN) in cross-sectional studies, but prospective data are scarce. This study aimed to assess the associations of biomarkers of subclinical inflammation and adiponectin with subsequent changes in heart rate (HR) and heart rate variability (HRV) in non-diabetic and diabetic individuals.MethodsData are based on up to 25,050 person-examinations for 8469 study participants of the Whitehall II cohort study. Measures of CAN included HR and several HRV indices. Associations between baseline serum levels of high-sensitivity C-reactive protein (hsCRP), interleukin (IL)-6, IL-1 receptor antagonist (IL-1Ra) and adiponectin and 5-year changes in HR and six HRV indices were estimated using mixed-effects models adjusting for age, sex, ethnicity, body mass index (BMI), metabolic covariates and medication. A modifying effect of diabetes was tested.ResultsHigher levels of IL-1Ra were associated with higher increases in HR. Additional associations with measures of HRV were observed for hsCRP, IL-6 and IL-1Ra, but these associations were explained by BMI and other confounders. Associations between adiponectin, HR and HRV differed depending on diabetes status. Higher adiponectin levels were associated with more pronounced decreases in HR and increases in three measures of HRV reflecting both sympathetic and vagal activity, but these findings were limited to individuals with type 2 diabetes.ConclusionsHigher IL-1Ra levels appeared as novel risk marker for increases in HR. Higher adiponectin levels were associated with a more favourable development of cardiovascular autonomic function in individuals with type 2 diabetes independently of multiple confounders.

Challenges of ECG monitoring and ECG interpretation in dialysis units

Patients on hemodialysis (HD) suffer from high cardiovascular morbidity and mortality due to high rates of coronary artery disease and arrhythmias. Electrocardiography (ECG) is often performed in the dialysis units as part of routine clinical assessment. However, fluid and electrolyte changes have been shown to affect all ECG morphologies and intervals. ECG interpretation thus depends on the time of the recording in relation to the HD session. In addition, arrhythmias during HD are common, and dialysis-related ECG artifacts mimicking arrhythmias have been reported. Studies using advanced ECG analyses have examined the impact of the HD procedure on selected repolarization descriptors and heart rate variability indices. Despite the challenges related to the impact of the fluctuant fluid and electrolyte status on conventional and advanced ECG parameters, further research in ECG monitoring during dialysis has the potential to provide clinically meaningful and practically useful information for diagnostic and risk stratification purposes.